1. Field of the Invention
This invention generally relates to pipe organs and, more particularly, to the efficient operation of valves which control the flow of air into pipes to produce musical sounds.
2. Description of Related Art
Although the pipe organ has a long history, spanning many centuries, as a musical instrument, it was not until the first half of the nineteenth century that organ builders provided organists with devices to assist in opening the valves to the pipes of such organs. Before that time, the organist had to manually operate the valves through a complex system of mechanical levers attached to the organ keyboard. These complex systems required the organist to supply all of the energy needed to manually operate the valves. In large systems having large valves, this required substantial energy and frustrated many organists.
However, in the twentieth century organ builders have made wide use of valves attached to lever magnets, as well as valves attached to pneumatic bellows or diaphragms, which in turn are activated by a magnetically controlled valve. In both instances this reduced the effort needed on the part of the organist, since the operation of the valve merely required the electrical closure of contacts attached to an organ keyboard.
Even though thousands of organs have been built using one form or another of these electrically operated valves, many organists and organ builders have found the performance of such organs substantially lacking. In particular, during the second half of the twentieth century, many organ builders have abandoned the use of electrically and/or magnetically operated valves and have returned to the building of organs using direct mechanical action to manually operate organ valves, much as their predecessors were doing centuries ago.
In order to understand this interesting phenomena, an understanding of how pipe organs produce sound is necessary. Sound is produced in organ pipes in a manner analogous to the way sound is produced in the woodwind instruments of an orchestra, such as flutes, clarinets, etc. This sound can in general be referred to as being in one of three states: (1) the "on" speech, sometimes referred to as the "attack"; (2) the sustain or continuous state; and (3) the "off" speech, sometimes referred to as the "decay". Every pipe organ produces these three states of sound. The attack and the decay speech, in particular, are of great importance. The attack is determined by how air under pressure is admitted to the pipe by the controlling valve, while the decay is determined by how flow of air under pressure to the pipe is interrupted by the controlling valve. It is the accurate and controlled opening and closing of electric or magnetic valves that has produced many problems for the organ builder and the organist.
Among those problems realized by the organ builder are those relating to efficiency. This occurs since even a modest size pipe organ will have in excess of a thousand pipes, thereby requiring an equal number of control valves. In such circumstances it is sometimes necessary to operate hundreds of valves simultaneously. This requirement brings on further problems, such as voltage drops in high current circuits, having large bundles or groups of wires, which large bundles of wires produce their own problems.
Another problem that frequently arises occurs in the hinges of valves attached to lever magnets. This is because ordinarily pipe organs may be considered to be "intermittent" devices, and during periods of inactivity, the hinges of the lever magnet valves may become corroded or somehow impaired. This impairment affects the operation of the valves, and this, in turn, causes their behavior to be inconsistent and erratic, especially during opening and closing of the valves. Additionally, lever magnets tend to be heavy because of the use of iron in the levers and other components. These heavy components require more energy to initially move the valve.
Lever magnets also ordinarily suffer from a lack of dampening in the closing of the valve, thus causing the valve to "bounce". This bounce, in turn provides an extra burst of air to the pipe, which is highly undesirable.
Known valves also suffer alignment and guide problems, resulting from, among other things, improper installation, which in turn results in improper seating of the valve to cut-off and/or control flow of air therethrough.
Therefore, in known electromagnetically operated valves for use in pipe organs, the organ builder and organist have been at the mercy of the above-mentioned eccentricities of the operation of the valves. That is, there has been practically no control over the closing and opening of such known valves, or the proper alignment thereof.
Besides the problems, or detrimental factors mentioned above, there is the fact that in known electromagnetically operated valves, the travel of the valve was extremely limited. Because of this limited travel, the valves operated by such devices were seldom, if ever, fully opened. Furthermore, in an effort to reduce the mass of the valves to conserve energy, construction of the component parts of the valves tended to be flimsy, subjecting the valves to being easily broken and undue wear, thereby requiring frequent repairs and/or replacements.
An example of a known electromagnetically operated valve for pipe organs, which overcame some of the problems discussed above, is disclosed in U.S. Pat. No. 4,851,800, in the name of Richard H. Peterson and Justin Kramer. However this patent did not overcome all of the problems mentioned above, and includes a return spring to aid the valve closure to return to the closed position.
A further example of a somewhat analogous electromagnetically operated device for percussion instruments, but which is not fully applicable to pipe organ valves and suffers from some of the problems mentioned above, is disclosed in U.S. Pat. No. 4,667,892, in the name of Justin Kramer and Richard H. Peterson.
There, therefore, exists a long-felt need in the art for a simplified, electromagnetically operated valve which meets the requirements of organ builders and organists alike. The valve set forth herein meets these requirements, and more, in an elegant and reliable manner to provide a valve which is easy and relatively inexpensive to manufacture, and which operates in a consistent and desired manner.